OPTICAL IMAGING SYSTEM

An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens has a negative refractive power. The second lens has a negative refractive power. The third lens has a positive refractive power. The fourth lens has a positive refractive and an object-side surface that is concave in a paraxial region thereof. The fifth lens has a positive refractive power. The sixth lens has a negative refractive power. The first to sixth lenses are sequentially disposed in ascending numerical order from an object side of the optical imaging system toward an imaging plane of the optical imaging system. Two lenses that are adjacent to each other among the first to sixth lenses are cemented to each other to form a cemented lens.